1. The mechanical behavior of textile composites (qualitative analysis) Yasser Gowayed Department of Textile Engineering Auburn University

2. Textile Composites Steady Improvements in weaving technology has increased the availability of textile preforms Advantages include ease of handling, ability to conform to complex shape and improved residual strength after impact Successful application requires accurate prediction of thermo-mechanical properties and the rate of damage accumulation to allow design engineers to predict when components should be removed from service (relationship between micro damage and mechanical properties)

3. Textile vs. Laminated Composites Laminated Composites Textile Composites High fiber vol. fraction High in-plane properties Low out-of-plane properties Low resistance to crack initiation and propagation Low fiber vol. fraction Low in-plane properties High out-of-plane properties Low resistance to crack initiation and high resistance to crack propagation

4. Mechanical behavior: The Effect of Yarn Crimp Intro to composites, Hull & Clyne Plain weave

5. T. Norman et al. FiberTex 92 Mechanical behavior: The Effect of Yarn Crimp Angle Interlock weave

6. Mechanical behavior: The Effect of Yarn Crimp XYZ orthogonal weave

7. Mechanical behavior: The Effect of Yarn Crimp 3D braids www.atlanticresearchcorp.com

8. Mechanical behavior: The Effect of Yarn Crimp Knits Univ. of Leuven, Belgium

9. Stitched Composites Mechanical behavior: The Effect of Yarn Crimp

10. Laminated Composites Textile Composite Mechanical behavior: The Effect of Yarn Crimp

11. Layup 0/90 +/- 45 WovenLaminate Woven Laminate Thickness (mm)2.552.17 2.632.18 Strength (MPa)545644 214216 Failure strain1.021.02 4.16.7 Modulus (GPa)50.260.1 16.317.1 Poissons ratio0.060.04 0.720.75 Tensile properties of carbon/epoxy composites: Bishop et al., Composites 84 Mechanical behavior: The Effect of Yarn Crimp

12. Layup Tensile Compressive WovenLaminate Woven Laminate 0/90 (Curtis, ICCM 85)597714 542613 +/- 45 (Bishop, AGARC 83) 11021218 899803 +/- 45 (Curtis, ICCM 85) 903892 815705 Tensile and Compressive strength (MPa) of carbon/epoxy composites: Mechanical behavior: The Effect of Yarn Crimp

13. Kollegal et al. Tensile behavior of AS4/epoxy plain weave with on and off-axis loads Mechanical behavior: The Effect of Yarn Crimp

14. Chian-Fong Yen et al. Tensile behavior of CVI SiC/SiC plain weave Mechanical behavior: The Effect of Yarn Crimp

15. Kollegal et al. Shear behavior of AS4/epoxy plain weave with on and off-axis loads Mechanical behavior: The Effect of Yarn Crimp

16. Mechanical behavior: The Effect of Yarn Crimp www.materials-sciences.com Local Fiber Failure Mechanisms Resulting from Compression of Kevlar/Epoxy Composites

17. Property3-D braidUnidirectional Tape Fiber Vol. Fraction0.170.35 Total Energy Absorbed (ft.lbs)19693.5 Crack initiation energy (ft.lbs)48.910.5 Crack propagation energy (ft.lbs)145.583 Maximum impact load (lbs)56002600 Impact Behavior Impact properties of Alumina/Al-Li composites Ko, et al. ASTM STP 964

18. Impact Behavior Bishop, Textile Structural Composites X-ray radiograph of fatigue damage at notches Micrographic images of fatigue damage at notches

19. Fatigue Behavior Bishop, Textile Structural Composites

20. Fatigue Behavior Bishop, Textile Structural Composites

21. Crack Initiation: The Effect of Yarn Crimp Laminated Composites Textile Composite (3D XYZ woven)

22. Laminated Composites Textile Composite (3D XYZ woven) Crack Growth: The Effect of Yarn Crimp

23. Crack Growth: Micrographic images Failure of plain weaves Univ. of Leuven, Belgium

24. Crack Growth: Micrographic images Failure of Angle Interlock weaves T. Norman et al. FiberTex 92

25. Crack Growth: Micrographic images Pretest condition of Angle Interlock weaves with stuffers

26. Crack Growth: Micrographic images Failure of Angle Interlock weaves with stuffers T. Norman et al. FiberTex 92

27. Textile Composites Imperfections - voids